Users of liquid-cooled diesel generator sets must understand that the use of pure water is bad for the engine. Pure water in the radiator will cause:

1. Scale formation inside radiator core, hoses, and engine water jacket, absorbing more heat.

2. Scale formation causes blockage of liquid flow leading to increased pressure and leaks.

3. Pure water will boil creating bubbles causing piston cylinder cavitation. (Figure 1).

4. Rust formation inside the radiator, radiator cap, and engine block.

5. The radiator cap acts as a valve during pressure and vacuum relief in the radiator tank (Figure 2). A rusty radiator cap will malfunction due to the seizure of its valve springs. (Figure 3).

6. Rust formation will cause water pump seizure or damage.

To prevent these, it is recommended to use a mixture of 50% distilled water and 50% ethylene-glycol-based coolant. Distilled water does not contain minerals which are the source of scale formation. 50-50 mixture will provide the following benefits:

1. Prevents scale formation.

2. Extends the boiling point of water and prevents bubble formation.

3. Prevents rust formation, and lubricates water pump, radiator cap, hoses, and engine block.

4. Efficient cooling system; prevents overheating.

5. Prevents engine breakdown.